11 Foods That Boost Your Immune System Naturally

By Hezy Evans| November 2, 2010

A weakened immune system can make your body vulnerable to various kinds of diseases and illness, particularly when it is warm seasonal shift from winter cold to summer.

The immune system is the gate keeper for your body. It protects the body from pathogens such as bacteria, viruses, parasites, and so forth. That’s why it is important to keep your immune system functioning at its optimum level.

Food plays a major role in your body’s immune system to function properly. Some foods are known may decrease your immunity, while others can help boost your immune system. Here are some best immune boosting foods that you should include in your diet to keep your body fit and healthy.

1. Citrus fruits

Citrus fruits, like lemons, oranges, and grapefruits, are high in vitamin C – a well known immune-boosting nutrient which is recognized for its antibacterial and anti-inflammatory properties.

Vitamin C also helps maintain the integrity of your skin, which acts as a protective barrier against infection. Therefore, getting enough vitamin C is a great way to strengthen your immune system and fight off colds and flu.

2. Garlic

Garlic contains an immune-stimulating compound called Allicin, which promotes the activity of white blood cells to fight colds and flu. Garlic also have antimicrobial and antiviral properties that may help fight bacterial and viral infections.

In one study, participants given a daily allicin supplement were 63 percent less likely to experience colds than the placebo group.

In another study, participants given a daily aged garlic extract supplement became sick just as frequently as the placebo group. However, they reported 21 percent fewer symptoms and recovered 58 percent more quickly than the placebo group.

3. Ginger

Like garlic, ginger also contains active compounds that may help lower the risk of infection and improve immune cells’ ability to fight off colds and flu.

Research shows that ginger has antimicrobial properties, which helps in treating infectious diseases. It’s also known for its ability to treat inflammatory disorders that are caused by infectious agents such as viruses, bacteria and parasites.

4. Onions

Onions are packed with immune-boosting nutrients like vitamin C, selenium, sulfur compounds, and zinc. Additionally, they also contain quercetin, a potent flavonoid that has antiviral properties as well as histamine regulating effects.

The pungency of onion increases your blood circulation and makes you sweat. This effect is very helpful during cold weather to prevent infections and to sweat out a cold or flu. Consuming raw onion within a few hours of the first symptoms of a cold or flu will produce a strong immune effect.

5. Tea

Both black and green tea are packed with polyphenols, a type of antioxidant which has been shown to enhance immune function.

A Harvard study showed that people who drank 5 cups of black tea per day for two weeks had 10 times more virus-fighting interferon in their blood than other who drank a placebo hot drink.

Both black tea and green tea are also rich in L-theanine, an amino acid that may aid in the production of germ-fighting compounds in your T-cells.

6. Honey

Honey has immune-boosting ability due to its antioxidant, antibacterial, and antimicrobial compounds which ward off bacteria to help fight infection in the body. Honey can also improve your digestive system, treat acid reflux, and heal wounds quickly.

Make a glass of lukewarm honey water mixed with a pinch of cinnamon powder to help boost your immune system and keep you healthy.

7. Berries

Berries are the perfect food to keep your immune system in tip-top shape and reduce inflammation. Berries, like blackberries, blueberries, and strawberries, contain polyphenols that are associated with fighting colds and flu.

Berries contain more antioxidants per serving than any other foods. Plus, berries are rich in vitamin C, making them a great choice for cold and flu season.

8. Probiotic foods

Probiotic foods are filled with good bacteria that helps with digestion and enhance your immune system.

A study published in the clinical journal Synthetic and Systems Biology found that a yogurt probiotic drink can help reduce symptoms of the common cold and the risk of upper respiratory infections.

During the study, scientists tested three different probiotic strains: Lactobacillus paracasei, Lactobacillus casei 431, and Lactobacillus fermentum (PCC). The findings suggest that the supplement was effective in staving off cold and flu-like respiratory infections by improving the immune system in patients who fell ill four or more times over the past year.

The other probiotic foods include yogurt, kefir, natto, kimchi, and tempeh.

9. Sweet potatoes

Sweet potatoes are another powerful immune boosting food. This because the tuber is rich in beta-carotene, one of the plant carotenoids that converts to vitamin A in the body. Vitamin A may help to stimulate the pro-inflammatory immune response to overcome infection.

The Recommended Dietary Allowance (RDA) for vitamin A is 3000 IU per day for men, 2300 IU per day for women, and 2500 UI per day for pregnant women.

The other foods rich in beta-carotene include carrots, pumpkins, squash, cantaloupe, and red peppers.

10. Nuts

Nuts, like almonds and walnuts, are rich sources of vitamin E, selenium, and zinc. All of these play an important role in maintaining a healthy immune system.

Nuts are also great sources of fiber and healthy fats, all of which are beneficial for health. Consuming nuts regularly will lower your cholesterol levels and improves your immunity.

11. Mushrooms

Mushrooms are high in selenium and B vitamins such as riboflavin and niacin. These nutrients are necessary for the immune system to function properly. Mushrooms also contain powerful compounds called beta-glucans, which have immune enhancing properties.

The beta-glucans in medicinal mushrooms, such as maitake, reishi, shiitake, chaga, and oyster mushroom, are especially notable for their ability to activate and modulate immune system cells.